The penetration depth of plasma treatment into porous media at atmospheric pressure

Summary form only given, as follows. The effects on fabrics of plasma treatment by these discharges were investigated with respect to the depth of penetration of plasma treatment. Stacks of ten thin layers of polypropylene nonwoven fabric sheets were exposed to both types of discharge operated in air. The surface energy increase of each individual layer was measured. Measurement was performed for materials of various porosities. While in the case of SBD the depth of treatment was given mainly by diffusion of active particles originated from the thin layer of discharge plasma, the depth of treatment was connected with the size of pores, probably because of limitations given by distance, over which a charge imbalance (Debye length) can exist.